To build your own guitar you need to plan the design, gather the materials and tools, cut the pieces, paint and polish them and finally assemble them. Then you have to just add the chords and tune the guitar. The process requires certain tools, as well as some woodworking skills.
You need to start with bookmatching, a process in which you cut a single piece of wood into two equally thick sheets and use it to carve the top and back of the guitar body. Then you do the strutting, where you glue wooden braces to the underside of the top piece. This offers resistance against the pull of the strings and more control over how the top piece vibrates. Then you glue the back similar to the top piece.
The next step is to carve the neck according to exact specifications and insert onto it the fingerboard. Next, attach the neck to the guitar body. The final part of the assembly is polishing the guitar and adding the bridge to the bottom part of the body so that you can place the strings. You also need to add the tuning machine to the top of the neck.
The process you follow also depends on how much you want to build yourself. You always have the option to order the parts online from websites such as byoguitar.com and just do the assembly.